In the field of oil and gas exploration/production, a well cellar can be positioned below ground level underneath a drilling rig. A well is drilled within the well cellar. The present application is directed to containment well cellars of the types generally described and claimed in U.S. Pat. Nos. 7,637,692, 7,987,904, 8,127,837, 8,256,505, and 8,485,250, each of which is hereby incorporated by reference in its entirety. These well cellars also may contain equipment such as blow out preventers, valves, and other equipment associated with drilling, completion and other well operations.
Outside of the well cellar designs described and claimed in the above-noted patents, other well cellars often are made only from a section of steel culvert pipe installed in the ground with a dirt floor. These other designs provide no protection against fluid spills that can arise during drilling operations. More specifically, during drilling, completion and other well operations, fluids from the drilling rig and production equipment, such as lubricants, drilling mud, completion fluids, and oil, can leak or spill into and out of the well cellar. These spills can create ecological problems, polluting soil samples as well as surface and subsurface aqueous sources. Such corrupted soil areas must be remediated before a well is capped, adding expense to taking an under-producing well off-line.
In the well cellars associated with the present application, the well conductor pipe extends through a well slot in the floor or base plate of the well cellar into the underlying subterranean formation. Preferably, the conductor pipe is cemented into place and then sealed to the floor or base plate to protect against fluid spills during operation. Preferably, the floor or base plate is also sealed to the wall or walls of the well cellar so that the walls not only provide structural support to prevent collapse of the surrounding earth onto the equipment, but also act to protect against fluid spills as well.
Many well pads have multiple parallel rows of wells, and equipment access to the wells is part of the layout planning. Where well cellars with floor or base plates, as described above, are used for such well pads, and the floor or base plates have predetermined or fixed locations for well slots into which a conductor pipe is placed, a need has arisen for an installation process that facilitates well pad construction and layout options for the operator (i.e., the customer).